Marijuana is known to be used quite a lot by many Sadhus in India, so one might wonder if there is a spiritual use of it. The answer is that there are some interesting spiritual opportunities in using Marijuana, but there is definitely no need for it. It all depends who is using Marijuana or other Cannabis products, with what intent and how.   

Many householder yogis will eat or drink Cannabis products rather than smoking Marijuana, which is obviously better for health. Addiction to Cannabis is fortunately limited to some mental/emotional/social dependency and does not include a strong addiction on the level of the body as it is found in many other drugs including alcohol.   

Over 100 active compounds are found in Marijuana, of which THC and CBD are the most important. THC gives the creative high associated with Marijuana, while CBD gives a kind of relaxation. Marijuana connects to  receptors for the neurotransmitter Anandamide. Since in yoga the bliss of Ananda is the primary goal, this also means that all other aspects of yoga can produce similar effects as Cannabis and we have to be careful that in chosing one, we do not drop the others.  

According to yogic science, Marijuana stimulates whatever lunar energy is already present, while it will also subdue the solar energy. In this way it may both stimulate artistic creativity, spiritual insight as well as paranoia. Less solar energy means less Ego, which means that while Marijuana smokers are relatively harmless, they may also tend to be lazy and without concentration or purpose.   

Marijuana is best used after sunset and not during the day. It will reduce the financial worries in first Chakra, enhance pleasure in second Chakra, reduce the Ego centered mindset in third Chakra, produce more love and Bhakti in 4th Chakra and bring some understanding on the relativity of any intellectual truths in 5th Chakra. In 6th Chakra where the main desire is to meditate, it is only useful at an advanced state, as it will separate mind from the Self. As long however as one has not mastered full mental concentration, combining meditation with the use of Marijuana is a waste of time.  

A main subject also is the correct dosing of Marijuana, which is more difficult compared to alcohol for example. To get some spiritual benefits from using Marijuana, a mild use with low doses is advisable in most cases and definitely upon frequent use.